ANORDNING VID EN MODULATOR FOR OMFORMNING AV EN LIKSTROMSSIGNALERINGSSIGNAL TILL EN PA EN BERFREKVENS MODULERAD VEXELSTROMSSIGNAL

摘要

A modulator for modulating an a.c. signal with a d.c. signal from a d.c. signal line, in which is provided a pulse shaping circuit the input of which is arranged to be connected alternatively to the d.c. signal line for closed-circuit feed or to the output of an inverter whose input is connected to the d.c. signal line for open-circuit feed, the pulse shaping circuit comprising a low-pass filter whose input arrangement cooperates with the d.c. signal line or the inverter output to provide independently adjustable time constants for closed - or open-circuit feed respectively and whose output is connected to modulating means for modulating the a.c. signal.